This invention relates to containers for receiving body fluid samples, and for containing those samples for subsequent examination to determine the presence or absence of disease in the samples. Generally speaking, such containers are in tube form and they may or may not be evacuated, depending upon the particular sample being taken. As will be understood by practitioners-in-the-art, evacuated tubes are used in great numbers for taking blood samples with the tubes frequently containing reagents for reacting with the blood samples for determining the presence or absence of disease.
The tubes may also be non-evacuated tubes for taking samples for one reason or another. Of course urine samples may also be taken in both evacuated and non-evacuated tubes. While non-evacuated tubes are utilized in great numbers, it is preferred to use evacuated tubes for many specific applications for maintaining a seal of the tube prior to use and for facilitating the entry of the sample into the evacuated tube for subsequent testing of the sample.
For evacuated tubes, in particular, it is important to maintain the vacuum over a period of time in order to provide appropriate storage life for those tubes prior to their being used. That is, it is important for the vacuum level to be maintained for a period of time prior to the time when a technician or a nurse uses the tube for receiving a blood sample, for example.
Many developments have been made in the past in order to provide plastic tubes for evacuated tube applications. However, plastic tubes have not been developed to the extent where they will maintain an appropriate vacuum for a period of time long enough to be satisfactory for a shelf-life which is appropriate under the circumstances in which such tubes are used. Moreover, various plastics have a tendency, in certain applications, to react adversely or interfere with blood chemistries, subsequently, during the actual testing of the sample in a lab. In some instances, the plastic may interfere with reactants contained in the tube for the purpose of reacting with a blood sample, for example, in order to provide an appropriate test result during examination.
Therefore, it is appropriate and conventional for tubes to be comprised of glass for use in evacuated tubes because glass maintains the vacuum for a much longer or indefinite period of time, and glass does not react adversely in most cases with any blood chemistry applications utilizing such tubes.
The difficulty, on the other hand, with the use of glass tubes is breakage. With the advent of the highly contagious AIDS virus in many people, it has become extremely important to avoid contamination of technicians, nurses and doctors by blood samples obtained by them from diseased patients.
As will be understood, glass tubes break and/or they may be cracked by being struck, inadvertently, against some object during the course of the taking of a sample or the course of the sample being delivered from a patient to the laboratory for subsequent testing. It will be understood, further, that such breakage and/or cracking may result in leakage of a diseased blood sample, for example, over the hands of the technician or the person taking the sample or the laboratory technician who is in the course of examining the sample for the presence of disease.
If that technician happens to have an open wound, the possibility of acquiring the AIDS virus or some other disease such as hepatitis, is substantial. Also, broken glass may cut and contaminate, and the pieces must be handled in order to be disposed of. Accordingly, great pains are being taken in the development of any materials utilized for taking and handling samples which contain diseases of this kind and it is to this situation to which this invention is particularly directed.
The invention here utilizes a clear transparent plastic tube configured to receive coaxially therein a clear transparent glass tube. The bottom curved internal surface of the plastic tube may contain ribs integral with the bottom surface of the plastic tube in order to stabilize and maintain the glass tube inserted therein in a coaxial position therewith. Subsequent to insertion of the glass tube within the plastic tube of the assembly of the invention herein, an interlock ring specifically arranged to maintain the coaxial positioning of the outer plastic tube with the inner glass tube is placed adjacent the top edge of the plastic and glass tubes. The interlock ring is specifically configured in order to maintain the integrity of this coaxial positioning and to provide appropriate stability for the assembly of the invention.
In addition, the ring includes an integral annular internal flap which "gives" during insertion of the glass tube into the plastic ring so as to frictionally grip the glass tube and hold it coaxially in place within the plastic tube. Thus, by having the entire outer surface of the glass tube covered by a plastic tube, if the glass tube is broken or cracked, in the kind of accident discussed above. The plastic tube around the glass tube contains the sample therein. Even though the sample may not be utilized for subsequent testing for the presence of disease because of the crack or break, at least the technician may contain the sample and dispose of it prior to any dripping or spilling and subsequent contamination. Also, the plastic tube shields the user from sharp broken edges and contains the shattered pieces of glass.
It will be understood that it makes no difference whether the glass tube is evacuated or not evacuated in accordance with this invention. The presence of this sleeve firmly attached to the outer surface of the glass container holding the sample has the effect of maintaining the general integrity of the container holding a sample so that it may be properly disposed of without any contamination to the user. In addition, the sleeve makes the container stronger over all because of the cushioning characteristics thereof.
As purely illustrative of a plastic sleeve material which may be used over a glass fluid specimen tube, in accordance herewith, one may note that the plastic sleeve or tube is preferably injection molded from a rigid thermoplastic material having high clarity and good impact resistance. Representative materials for this purpose include, for example, polyethylene terephthalate, styrene acrylonitrile, acrylonitrile-butadiene-styrene, polycarbonate, or other thermoplastic materials having the high clarity and good impact resistance required. The interlock ring utilized, in accordance herewith is comprised of a resilient material in order to develop "snap-lock" properties so that the ring may be snapped in place inside and around the top edge of the plastic sleeve, and may again be resiliently deformed for receiving the glass tube therein in order to hold the entire assembly in its desired coaxial position.
As a further feature of the invention, a curable filler or adhesive may be used along a portion of the adjacent opposed surfaces of the glass and plastic tubes particularly near the bottom closed ends thereof in order to maintain the two tubes fixed relative to each other in their desired coaxial position. Moreover, as discussed above, the internal bottom surface of the plastic tube may include integral ribs around the circumferential edge of the bottom internal surface for engaging the outer surface of the glass tube.
With the foregoing and additional objects in view, this invention will not be described in more detail and other objects and advantages thereof will be apparent from the following description, the accompanying drawings, and the appended claims.
As purely illustrative of an arrangement of container assembly which may be used for carrying out this invention, one may note the attached drawings in which a preferred embodiment of such a container is shown utilizing the coaxially arranged glass and plastic container assembly of the invention.